Which preposition correctly completes this sentence: 'The government has taken measures to guard ______ potential risks in infrastructure projects'?
答案解析
核心考点：动词固定搭配 解题思路：'guard against'为固定搭配，意为'防范'。选项分析：B项'guard for'表目的，不符合语境；C/D项介词搭配错误。 易错点提醒：注意区分相似介词搭配的不同含义，如'guard against'（预防）与'guard from'（保护免受）的区别。
正确答案：A